package com.blueocean_health.care.management.util;
import java.awt.image.BufferedImage;  
import java.io.File;  
import java.io.IOException;  
import java.math.BigDecimal;  
  
import javax.imageio.ImageIO;

import com.blueocean_health.care.management.common.base.string.StringUtils;

import net.coobird.thumbnailator.Thumbnails;  
  
public class PicUtils {  
  
    public static void main(String[] args) {  
  
        PicUtils.commpressPicForScale("C:\\Users\\123\\Desktop\\1.png",  
                "C:\\Users\\123\\Desktop\\12.jpg", 500, 0.8); // 图片小于500kb  
    }  
  
    /** 
     * 根据指定大小和指定精度压缩图片 
     *  
     * @param srcPath 
     *            源图片地址 
     * @param desPath 
     *            目标图片地址 
     * @param desFilesize 
     *            指定图片大小，单位kb 
     * @param accuracy 
     *            精度，递归压缩的比率，建议小于0.9 
     * @return 
     */  
    public static String commpressPicForScale(String srcPath, String desPath,  
            long desFileSize, double accuracy) {  
        if (StringUtils.isEmpty(srcPath) || StringUtils.isEmpty(srcPath)) {  
            return null;  
        }  
        if (!new File(srcPath).exists()) {  
            return null;  
        }  
        try {  
            File srcFile = new File(srcPath);  
            long srcFileSize = srcFile.length();  
            System.out.println("源图片：" + srcPath + "，大小：" + srcFileSize / 1024  
                    + "kb");  
           if(srcFileSize<=desFileSize*1024){
        	   return srcPath;  
           }
            // 1、先转换成jpg  
            Thumbnails.of(srcPath).scale(1f).toFile(desPath);  
            System.out.println("jpg目标图片：" + desPath + "，大小" + new File(desPath).length()  
            / 1024 + "kb");  
            // 递归压缩，直到目标文件大小小于desFileSize  
            commpressPicCycle(desPath, desFileSize, accuracy);  
  
            File desFile = new File(desPath);  
            System.out.println("目标图片：" + desPath + "，大小" + desFile.length()  
                    / 1024 + "kb");  
            System.out.println("图片压缩完成！");  
        } catch (Exception e) {  
            e.printStackTrace();  
            return null;  
        }  
        return desPath;  
    }  
  
    private static void commpressPicCycle(String desPath, long desFileSize,  
            double accuracy) throws IOException {  
        File srcFileJPG = new File(desPath);  
        long srcFileSizeJPG = srcFileJPG.length();  
        // 2、判断大小，如果小于500kb，不压缩；如果大于等于500kb，压缩  
        if (srcFileSizeJPG <= desFileSize * 1024) {  
            return;  
        }  
        System.out.println("目标图片中：" + desPath + "，大小" + srcFileJPG.length()  
        / 1024 + "kb");  
        // 计算宽高  
        BufferedImage bim = ImageIO.read(srcFileJPG);  
        int srcWdith = bim.getWidth();  
        int srcHeigth = bim.getHeight();  
        int desWidth = new BigDecimal(srcWdith).multiply(  
                new BigDecimal(accuracy)).intValue();  
        int desHeight = new BigDecimal(srcHeigth).multiply(  
                new BigDecimal(accuracy)).intValue();  
  
        Thumbnails.of(desPath).size(desWidth, desHeight)  
                .outputQuality(accuracy).toFile(desPath);  
        commpressPicCycle(desPath, desFileSize, accuracy);  
    }  
  
}  